Power tool



D. E. SCHOTT Aug. 27, 1968 POWER TOOL Filed Dec. 22, 1966 INVENTOR DONALD E. SCHOTT ATTORNEYS United States Patent 3,398,609 POWER TOOL Donald E. Schott, Emerson, N.J., assignor to Thomas C. Wilson Inc.', a corporation of New York Filed Dec. 22, 1966, Ser. No. 603,919 9 Claims. (Cl. 77-7) ABSTRACT OF THE DISCLOSURE In the use of power tools, such as saws or drills performing a cutting or drilling action where precision tolerances, smooth working surfaces and increased tool life are desired, the practice is to spray a cooling and lubricating fluid on the cutting surface continuously during the cutting operations. Depending upon the type of cutting being performed, it is desirable to spray the fluid as either a solid stream or as an atomized spray. It is the purpose of the invention to provide means in a power tool for effecting this spraying action during the normal operation of the tool.

' Broadly stated, the invention is in a power tool for use in performing cutting actions which has means for cutting-and a body member supporting the cutting means. The improvement in the combination is in fluid spray means which includes a first valve means for receiving air under pressure and fluid from respective sources and a nozzle assembly positioned adjacent the cutting means for spraying fluid in the cutting area and interconnected with said first valve means for receiving air and fluid from the first valve means. A second valve means is included in the nozzle for regulating flow of fluid and air so that fluid or atomized fluid can be sprayed from the nozzle. The fluid spray means is particularly adaptable for use with air powered tools since the air source is then readily available.

The nozzle assembly preferably has a nozzle body which includes an outlet through which fluid is dispensed, fluid inlet means entering the nozzle body and connected to the body outlet, and air inlet means entering the 'assemblyadja'cent'the body outlet. A nozzle cap having a cap outlet is mounted on the nozzle'body and is movable with respect to the body to a first position wherein the body and cap outlets are directly connected and prevent air flow through the cap outlet, and to a second position where the outlets of the body and cap are spaced from each other and open to the air to atomize the fluid as it flows from the cap outlet. I

A preferred embodiment of the invention is described hereinbelow with reference to the drawing wherein:

FIG. 1 is a side elevation partly in section of an air powered drill incorporating the fluid spray device; and

FIG. 2 is an enlarged section of the nozzle assembly of the fluid spray device.

An air power drill 10 is shown having a motor housing assembly 11, and integral handle assembly 12, and a chuck 13 extending from the housing assembly and holding a drill bit 14.

In this embodiment, the drill is air driven and therefore an air hose 15 is threaded into the base of the handle assembly 12 and attached thereby to a suitable thread connector 16. The thread connector 16 opens into a ball valve assembly 17. The ball valve assembly 17 is com- 3,398,609 Patented Aug. 27 1968 prised of a valve seat insert 18 which contains a ball 19 and a spring 20 which biases the ball toward the outlet opening in the valve seat and thereby normallymaintains the opening in the valve seat closed. An air inlet channel 22 extends from the valve seat opening 21 to the air powered motor 23 in the motor housing assembly.

Extending from the handle assembly 12 in the normal position is a trigger assembly 25 which in this embodiment comprises a trigger 26 slidable in a trigger insert 27. Extending into the trigger insert 27 is a first portion .28 of a bell crank 29 which is pivotally mounted so that a second portion 30 of the bell crank contacts a valve pin 31 which is mounted for abutment against the ball ,19.in the ball valve assembly. By this arrangement, when the trigger 26 is squeezed it displaces the bell crank and valve pin and opens the ball valve assembly for air flow to drive the motor.

Mounted on the back end of the motor housing assembly 11 is a first air and fluid valve assembly 33. This assembly is comprised of a generally tubular valve body 34 which has a stepped diameter bore 35 extending axially through the valve body. The bore 35, by the change in diameter, is divided essentially into a fluid chamber 36 at one end of the body and an air chamber 37 at the opposite end of the body which is joined by an intermediate linking chamber 38 positioned therebetween'. The valve body is connected adjacent its air chamber to the rear end of the motor housing 11 and is open to the air inlet chamber 22. Connected to the fluid chamber 36 at the opposite end of the valve body by means of a swivel connector 39 is a hose 40 carrying fluid from its source.

Positioned in the fluid chamber 36 and seating on the swivel connector 39 is a spring 41 and a ball 42 which provides ball valve assembly with the ball seating against a shoulder portion 43 defined by the reduction in diameter from the fluid chamber to the intermediate chamber 38. Abutting the ball 42 and extending axially through the intermediate chamber 38 is a piston rod 44 which has an integral piston 45 slidable in the air chamber 37 and positioned at the end thereof opposite to the end contacting the ball 42. The piston 45 has a suitable seal 46 mounted on the side thereof opposite tothe extension of the piston rod 44 and a stepped diameter cylindrical tubular member 47 extends axially toward the motor housing and has .a bore 47 extending axially into the member 47 from the channel 22 and opens radially out wardly of this member. The air chamber 37 is defined by an enlarged diameter portion adjacent the open end and opening into this enlarged portion is an air outlet tube 49 which extends through the wall of the valve body and forward of the motor housing to connect to a nozzle assembly 50 adjacent the chuck 13. Opening into the intermediate chamber 38 is a fluid tube 51 which also extends outwardly through the valve body to the nozzle assembly 50.

The nozzle assembly 50 is comprised of a nozzle body 52 which has an axially extending air chamber 53 and axially extending fluid chamber 54 into which the ends of the air and fluid tubes 49 and 51 extend and are secured to the nozzle body. The nozzle body has a generally conically shaped forward portion 55 with a reduced aperture 56 extending from the apex of the conical end portion. The aperture 56 is connected to the fluid chamber 54 and serves as the outlet for the fluid. The second larger aperture 57 opens out of the conical wall 58 of the nozzle body and it serves as the outlet for the air from the air chamber 53. Threaded to the nozzle body is a nozzle cap 60. The nozzle cap has a generally cylindrical portion 61 and a forward conically shaped portion 62 with the angle of the conical portion of the nozzle body relative to the axis of the assembly being less than the angle of the inner wall 63 of the conical portion 62 of the nozzle cap relative to the axis of the assembly. Extending substantially axially through the apex of the conical portion 62 of the nozzle cap is an outlet 64 which is coaxially aligned with the aperture 56 in the nozzle body. Thus, by the relative configuration of the nozzle assembly, a second fluid and air valve assembly is provided.

In operation, squeezing of the trigger 26 will activate the ball valve assembly 17 causing air under pressure of about 90 pounds p.s.i. to enter into the motor housing and drive the air powered motor causing the drill to be activated. The first air and fluid valve assembly 33 is simultaneously activated by the air entering the air chamher 37 and causing the piston 45 to be axially displaced rearwardly toward the fluid chamber 35. While some air forces the piston rearwardly, other air is allowed to travel through the air tube 49 and to the nozzle 50. Upon displacement of the piston 45 rearwardly, the piston rod unseats the ball 42 from its'valve seat 43 and allows a lubrieating and cooling fluid to pass into the intermediate chamber 38 and outwardly through fluid tube 51 to the nozzle 50.

Referring now to FIG. 2, when the forward end of the nozzle 55 is spaced from the nozzle cap 62, air can flow through chamber 53 and out the air outlet 57 for mixture with fluid flowing through the fluid chamber 54 and out the fluid outlet 56. The space defined between the inner wall 63 of the nozzle cap and the forward end of the conically shaped nozzle body will then function as a mixing chamber 65 and the fluid passing through the nozzle cap outlet 64 will be entrained in the air and be sprayed from the cap as atomized fluid.

If the nozzle cap 60 is threaded back on the nozzle body 52 so that forward end of the nozzle body is in contact with the inner wall 63 of the nozzle cap, no air will flow through the outlet 64 in the nozzle cap and a solid stream of fluid will be sprayed from the nozzle 50. Since there is a differential between the pressure of the fluid and the pressure of the air, as the nozzle cap is moved forward on the nozzle 55 so that the nozzle 55 is only slightly backed away from the inner wall 63 of the nozzle cap, the air pressure flowing out the nozzle cap outlet actually reduces the resistance to fluid flow from the nozzle or creates a partial vacuum which causes maximum fluid to be dispensed from the nozzle and entrained in the air as atomized fluid. Further movement of the nozzle cap away from the nozzle 55 so that the inner wall 63 of the nozzle cap is substantially spaced from the nozzle outlet 56 begins to cause a back pressure at the fluid outlet 56 of the nozzle which impairs fluid flow from the nozzle,

thereby reducing the amount of fluid entrained in the air to permit more economical use of the fluid when less volume is required.

When the trigger is released and the tool stopped, the

air flow also ceases and the first valve assembly closes and prevents any fluid passage or air passage to the nozzle 50 thereby permitting the most economic use of the fluid.

I claim:

1. In a power tool for use in performing cutting actions having means for cutting and a body member supporting said cutting means, the improvement in fluid spray means in combination therewith comprising first valve means for receiving air under pressure and fluid from respective sources, a nozzle assembly interconnected with the first valve means for receiving air and fluid from the first valve I 4 1 means, said nozzle assembly positioned adjacent the cutting means for spraying fluid in the cutting area, and a second valve means in the nozzle for regulating flow of fluid and air so that fluid or atomized fluid can be sprayed from the nozzle.

2. A tool according to claim 1 wherein it is air powered.

3. A tool according to claim 1 wherein said nozzle assembly comprises a nozzle body having an outlet through which fluid is dispensed, fluid inlet means entering the body and connected to the body outlet, air inlet means entering into the assembly adjacent the body outlet, a nozzle cap having an outlet and mounted on said nozzle body, the cap movable with respect to said body to a first position wherein the body and cap outlets are directly connected and prevent air flow through the cap outlet and a second position where the outlets of the body and the cap are spaced from each other and open to the air to atomize the fluid as it flows from the cap orifice.

4. A tool according to claim 3 wherein the outside of said nozzle body tapers toward said body outlet and the inside of said cap tapers toward the cap outlet with the angle of the tapered portion of the body relative to the axis of the assembly being less than the angle of the tapered portion of the cap relative to the axis of the assembly and thereby defining a chamber between the inside of the cap and the outside of the nozzle into which the air inlet opens.

5. A tool according to claim 4 wherein the air inlet extends through the body member and opens into the chamber.

6. A tool according to claim 1 wherein said first valve comprises a valve body, a first air chamber in said body having an inlet from an air source and an outlet to the nozzle assembly, a second fluid chamber in said body having an inlet from a fluid source and an outlet to the nozzle assembly, and a valve movable in said fluid chamber to open and close the fluid outlet in response to air flow in the air chamber.

7. A tool according to claim 6 wherein said valve in said fluid chamber is movable by a piston member located in said air chamber, said piston being responsive to changes in air pressure in said first chamber and to open and close the valve upon respective increase and decrease in air pressure.

8. A power tool according to claim 3 wherein said first valve comprises a valve body, a first air chamber in said body having an inlet from an air source and an outlet to the nozzle assembly, a second fluid chamber in said body having an inlet from a fluid source and an outlet to the nozzle assembly, and a valve movable in said fluid chamber to open and close the fluid outlet in response to air flow in the air chamber.

9. A tool according to claim 7 wherein said tool is air powered, and actuating the power tool opens the valve to permit fluid flow through the nozzle.

References Cited UNITED STATES PATENTS FRANCIS s. HUSAR, Primary Examiner. 

